title: Pollen flow in fragmented landscapes maintains genetic diversity following stand-replacing disturbance in a neotropical pioneer tree, Vochysia ferruginea Mart.
abstract: In forests with gap disturbance regimes, pioneer tree regeneration is typically abundant following stand-replacing disturbances, whether natural or anthropogenic. Differences in pioneer tree density linked to disturbance regime can influence pollinator behaviour and impact on mating patterns and genetic diversity of pioneer populations. Such mating pattern shifts can manifest as higher selfing rates and lower pollen diversity in old growth forest populations. In secondary forest, where more closely related pollen donors occur, an increase in biparental inbreeding is a potential problem. Here, we investigate the consequences of secondary forest colonisation on the mating patterns and genetic diversity of open-pollinated progeny arrays for the long-lived, self-compatible pioneer tree, Vochysia ferruginea, at two Costa Rican sites. Five microsatellite loci were screened across adult and seed cohorts from old growth forest with lower density, secondary forest with higher density, and isolated individual trees in pasture. Progeny from both old growth and secondary forest contexts were predominantly outcrossed (tm=1.00) and experienced low levels of biparental inbreeding (tm-ts=0.00-0.04). In contrast to predictions, our results indicated that the mating patterns of V. ferruginea are relatively robust to density differences between old growth and secondary forest stands. In addition, we observed that pollen-mediated gene flow possibly maintained the genetic diversity of open-pollinated progeny arrays in stands of secondary forest adults. As part of a natural resource management strategy, we suggest that primary forest remnants should be prioritised for conservation to promote restoration of genetic diversity during forest regeneration.
authors.affiliation: 1] Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia [2] NERC Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, Scotland, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Davies
authors.affiliation: NERC Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, Scotland, UK.
authors.forename: S
authors.initials: S
authors.lastname: Cavers
authors.affiliation: Centro Agronómico Tropical de Investigación y Enseñanza, Turrialba, Costa Rica.
authors.forename: B
authors.initials: B
authors.lastname: Finegan
authors.affiliation: Department of Mathematics, Heriot-Watt University, Edinburgh, UK.
authors.forename: A
authors.initials: A
authors.lastname: White
authors.affiliation: Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia.
authors.forename: M F
authors.initials: MF
authors.lastname: Breed
authors.affiliation: 1] Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia [2] Department of Environment and Natural Resources, State Herbarium of South Australia, Science Resource Centre, Adelaide, SA, Australia.
authors.forename: A J
authors.initials: AJ
authors.lastname: Lowe
mesh_terms: D003364:Costa Rica; D018744:DNA, Plant / Q000235:genetics; D065928:Forests; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D019684:Magnoliopsida / Q000235:genetics; D018895:Microsatellite Repeats; D008957:Models, Genetic; D011058:Pollen / Q000235:genetics*; D011156:Population Density; D012098:Reproduction / Q000235:genetics; D012639:Seeds / Q000235:genetics; D014197:Trees / Q000235:genetics*
chemical_list: D018744:DNA, Plant